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Naturally formed forest patches known as tree islands are found within lower-statured wetland matrices throughout the world, where they contrast sharply with the surrounding vegetation. In some coastal wetlands they are embedded in former freshwater marshes that are currently exposed to saltwater intrusion and mangrove encroachment associated with accelerating sea-level rise. In this study we resurveyed tree composition and determined environmental conditions in tree islands of the coastal Florida Everglades that had been examined two decades earlier. We asked whether tree islands in this coastal transition zone were differentiated geomorphologically as well as compositionally, and whether favorable geomorphology enabled coastal forest type(s) to maintain their compositional integrity against rising seas. Patterns of variation in geomorphology and soils among forest types were evident, but were dwarfed by differences between forest and adjacent wetlands. Tree island surfaces were elevated by 12–44 cm, and 210Pb analyses indicated that their current rates of vertical accretion were more rapid than those of surrounding ecosystems. Tree island soils were deeper and more phosphorus-rich than in the adjoining matrix. Salinity decreased interiorward in both tree island and marsh, but porewater was fresher in forest than marsh in Mixed Swamp Forest, midway along the coastal gradient where tropical hardwoods were most abundant. Little decrease in the abundance of tropical hardwood species nor increase in halophytes was observed during the study period. Our data suggest that geomorphological differences between organic tree island and marl marsh, perhaps driven by groundwater upwelling through more transmissive tree island soils, contributed to the forests’ compositional stability, though this stasis may be short-lived despite management efforts.

The rapid human-driven changes in the environment during the Anthropocene have placed extreme stress on many plants and animals. Beneficial interactions with microorganisms may be crucial for ameliorating these stressors and facilitating the ecosystem services host organisms provide. Foliar endophytes, microorganisms that reside within leaves, are found in essentially all plants and can provide important benefits (e.g., enhanced drought tolerance or resistance to herbivory). However, it remains unclear how important the legacy effects of the abiotic stressors that select on these microbiomes are for affecting the degree of stress amelioration provided to their hosts. To elucidate foliar endophytes' role in host-plant salt tolerance, especially if salinity experienced in the field selects for endophytes that are better suited to improve the salt tolerance of their hosts, we combined field collections of 90 endophyte communities from 30 sites across the coastal Everglades with a manipulative growth experiment assessing endophyte inoculation effects on host-plant performance. Specifically, we grew350 red mangrove (Rhizophora mangle) seedlings in a factorial design that manipulated the salinity environment the seedlings experienced (freshwater vs. saltwater), the introduction of field-collected endophytes (live vs. sterilized inoculum), and the legacy of salinity stress experienced by these introduced endophytes, ranging from no salt stress (0 parts per thousand [ppt] salinity) to high salt stress (40 ppt) environments. We found that inoculation with field-collected endophytes significantly increased mangrove performance across almost all metrics examined (15%-20% increase on average), and these beneficial effects typically occurred when the endophytes were grown in saltwater. Importantly, our study revealed the novel result that endophyte-conferred salinity tolerance depended on microbiome salinity legacy in a key coastal foundation species. Salt-stressed mangroves inoculated with endophyte microbiomes from high-salinity environments performed, on average, as well as plants grown in low-stress freshwater, while endophytes from freshwater environments did not relieve host salinity stress. Given the increasing salinity stress imposed by sea level rise and the importance of foundation species like mangroves for ecosystem services, our results indicate that consideration of endophytic associations and their salinity legacy may be critical for the successful restoration and management of coastal habitats.

As sea level rises in low-lying coastal islands, salt-tolerant (halophytic) coastal vegetation communities may be able to migrate inland, replacing the freshwater vegetation that is unable to tolerate salt stress. The pace of such shifts may be accelerated by a self-reinforcing feedback between the halophytic vegetation and salinity, as well as by frequent and intensified salinity pulses associated with the increasing impact of storm surges as a consequence of sea-level rise. We used a modification of a previously published spatially explicit individual-based model that simulates impacts on upland freshwater hammock communities from sea-level rise and storm surge to predict the interaction between three coastal communities: mangroves, hammocks, and pinelands. The model simulation predicted two qualitative characteristics regarding the interaction between these three different coastal communities: (1) mangroves and hammock communities tend to have ground water with high salinities, while at the same time pineland ground water salinity is low, and (2) pineland located at lower elevation relative to adjacent hammock will be negatively influenced by higher ground water salinities in hammocks, as it flows toward the lower elevation pineland. We tested these predictions using foliar δ13C of Conocarpus erectus collected from Big Pine Key as a proxy for ground water salinity. Measurements of ground water salinity via this proxy confirmed the two predictions of the model. Our approach provides an approximation of the impacts of sea-level rise on terrestrial vegetation communities, including threatened pineland communities, and can be used as a tool for management decisions.

Phylogenetic constraints on ecophysiological adaptations and specific resource requirements are likely to explain why some taxonomic/functional groups exhibit different richness patterns along climatic gradients. We used interpolated species elevational distribution data and climatic data to describe gymnosperm species richness variation along elevational and climatic gradients in the Himalayas. We compared the climatic and elevational distributions of gymnosperms to those previously found for bryophytes, ferns, and angiosperm tree lineages to understand the respective drivers of species richness. We divided our study location into three regions: Eastern; Central; and Western Himalayas, in each calculating gymnosperm species richness per 100-m band elevational interval by determining the sum of species with overlapping elevational distributions. Using linear regression, we analyzed the relationship between species’ elevational mid-point and species’ elevational range size to test the Rapoport’s rule for gymnosperms in the Himalayas. Generalized linear models were used to test if potential evapotranspiration, growing degree days, and the number of rainy days could predict the observed patterns of gymnosperm species richness. We used the non-linear least squares method to examine if species richness optima differed among the four taxa. We found supporting evidence for the elevational Rapoport’s rule in the distribution of gymnosperms, and we found a unimodal pattern in gymnosperm species richness with elevation, with the highest species richness observed at ca. 3000 m. We also found a unimodal pattern of gymnosperm species richness along both the potential evapotranspiration and growing degree day gradients, while the relationship between species richness and the number of rainy days per year was non-significant. Gymnosperm species richness peaked at higher elevations than for any other plant functional group. Our results are consistent with the view that differences in response of contrasting plant taxonomic groups with elevation can be explained by differences in energy requirements and competitive interactions.

Tree species in coastal forests may exhibit specialization or plasticity in coping with drought through changes in their stomatal morphology or activity, allowing for a balance between gas exchange and water loss in a periodically stressful environment. To examine these responses, we sought to answer two primary research questions: a) how is variation in B. simaruba’s stomatal traits partitioned across hierarchical levels, i.e., site, tree, and leaf; and b) is variation in stomatal traits an integrated response to physiological stress expressed across the habitat gradient of Florida Keys forests? At eight sites distributed throughout the Keys, five leaves were collected from three mature trees for stomatal analysis. Leaf carbon stable isotope ratio (δ13C) was determined to infer the changes in water use efficiency caused by physiological stress experienced by each tree. The results showed that substantial proportions of the total variance in three traits (stomatal density, stomatal size, and δ13C) were observed at all levels, suggesting that processes operating at each scale are important in determining trait values. A significant negative correlation between stomatal density and size across scales was observed. Path model analysis showed that environmental variables, distance to ground water and ground water salinity, affect leaf δ13C indirectly, via its effects on stomatal traits, not directly to leaf δ13C. Therefore, the combination of small and densely distributed stomata seems to represent a strategy that allows B. simaruba to conserve water under conditions of physiological drought induced by either higher ground water salinity or flooding stress at very low elevation.

Introduction: Catatonia is still an ill-understood phenomenology and we could not find any case based publications from Nepal. This study was undertaken to observe the proportion of catatonic patients in a year, to describe their frequencies, and to relate catatonia to mode of onset of catatonia, stressors and to diagnostic categories.Method: One-year prospective study was carried out in Psychiatry Ward of B. P. Koirala Institute of Health Sciences, Dharan. Socio-demographic variables were collected in structured Performa and Semi-Structured Performa was used for number of catatonic signs, life events, and mode of onset. Catatonia was screened and rated by Bush-Francis Catatonia Rating Scale. Psychiatric diagnoses were based on International Classification of Mental and Behavioral Disorder, Diagnostic and Research Guidelines, tenth version. Medical diagnoses were made by the consultant in Internal Medicine. Those who could not be admitted at least 24 hours for observation were not taken into study and 2 cases were excluded due to extreme of ages.Result: The proportions of patients with catatonia were 9.3% in psychiatric in-patients. Mutism was the most common sign and larger proportion had retarded catatonia. Mode of onset of catatonia, stressors, and disorders were not related. Medical and psychiatric catatonia could not be differentiated from the pattern of catatonic signs, even though echolalia occurred only in seizure disorder in our sample.Conclusion: The phenomenon of catatonia is common in our set-up. Mutism was the most common symptom. It is important to rule out organic etiology first. Depression is a common diagnosis with catatonia.

This study aims to find the altitudinal distribution pattern of vascular plant species reported from high mountain of Nepal (Manang) along the whole Himalayan elevation gradient, and evaluate their fate against climate change. Data was gathered from multiple sources, field investigations, literatures, and herbarium specimens. Altogether, 303 vascular plant species were reported from Manang. We used a published data to calculate distribution range of each species by interpolating between its upper and lower elevation limits. The relationship between elevation and species richness is elucidated by generalized linear model. The consequence of global warming upon Manang's vascular plant species was estimated based on projected temperature change for next century and adiabatic lapse rate along the elevation gradient of the Himalayas. The vascular plant species richness has a unimodel relationship with elevation along the whole elevation gradient of Nepal as well as in three biogeographical regions of Nepal. Vascular plants of Manang are found distributed from low land Terai to high alpine regions of Nepal and their elevation distribution range varies from 200 to 4700 m. Out of 303 vascular plants of Manang, only seven species might be affected if temperature increase by 1.5°C, whereas at least 70 species will be affected with 5°C temperature increased. However, the majority of species (233 species) have wider distribution range (> 1000 m) and more than 5°C temperature tolerance range, thus they are likely to be less affected from global warming by the end of 21st century.

Invasive plant species are exerting a serious threat to biological diversity in many regions of the world. To understand plant invasions this study aims to test which of the two plant invasiveness hypotheses; ‘low native diversity’ vs. ‘high native diversity’, is supported by the regional distribution patterns of invasive plant species in the Himalayas, Nepal. This study is based on data retrieved from published literatures and herbarium specimens. The relationship between invasive plant species distribution patterns and that of native plant species is elucidated by scatter plots, as well as by generalized linear models. The native plant species and invasive plant species have similar distribution patterns and the maximum number of invasive plant species is found in the same altitudinal range where the highest richness for native tree species is found. There is a clear trend of higher invasive plant richness in regions where native tree species richness is relatively high. Consequently, the native plant richness is highest in the central phytogeographic region, followed by the eastern and the western regions, respectively. The invasive plant species also follows a similar trend. Additionally, the invasive plant species richness was positively correlated with anthropogenic factors such as human population density and the number of visiting tourists. This study supports the hypothesis that ‘high native diversity’ supports or facilitates invasive plant species. Further, it indicates that native and invasive plant species may require similar natural conditions, but that the invasive plant species seem more dependent and influenced by anthropogenic disturbance factors.

The Everglades is a low-nutrient ecosystem occupied by marsh plant species adapted to low avail- ability of phosphorus. Recently, however, tree islands that are scattered throughout the marsh have been recognized as biogeochemical hotspots. The goal of this study was to determine the general patterns of response by common tree species when conditions limiting to optimal growth were improved by fertilization in an experimentally con- structed and managed Everglades wetland. Thirty-six trees of two species, Annona glabra and Chrysobalanus icaco, were randomly selected on two peat- and two limestone-based islands. Each tree was treated with one of three nutrient regimes: Nitrogen (N), Phosphorus (P), or Control (no addition of nutrients). Positive highly significant P-treatment effects on leaf total P and leaf N:P were observed in both species in comparison to Control trees, but neither species exhibited a similar response to N-fertilization. However, among the two species, only A. glabra responded to P-fertilization with increased growth. Both fertilized and unfertilized trees of each species exhibited a highly significant growth re- sponse to hydrological condition, with growth enhanced on less persistently flooded sites. Our experimental results identify a clear difference in species growth responses to substrate type in the two species, but do not support the idea that a single critical N:P ratio can be used to indicate nutrient limitation for all wetland trees.